JP5111817B2 - Fixed constant velocity universal joint - Google Patents

Description

  The present invention relates to a fixed type constant velocity universal joint, and more particularly to a fixed type that is used in a power transmission system of automobiles and various industrial machines, and that allows only angular displacement between two axes of a driving side and a driven side. It relates to a universal joint.

  For example, there is a fixed type constant velocity universal joint as a kind of constant velocity universal joint used as means for transmitting rotational force from an engine of an automobile to wheels at a constant speed. This fixed type constant velocity universal joint has a structure in which two shafts on the driving side and the driven side are connected and the rotational torque can be transmitted at a constant speed even if the two shafts have an operating angle. In general, as the above-mentioned fixed type constant velocity universal joint, a Barfield type (BJ) and an undercut free type (UJ) are widely known.

  For example, a UJ type fixed type constant velocity universal joint is an outer member in which a plurality of track grooves 2 are formed along the axial direction at equal intervals in the circumferential direction on the inner spherical surface 1 as shown in FIGS. An outer ring 3, an inner ring 6 as an inner member in which a plurality of track grooves 5 paired with the track grooves 2 of the outer ring 3 are formed on the outer spherical surface 4 along the axial direction at equal intervals in the circumferential direction, and the outer ring 3 Between the track groove 2 of the inner ring 6 and the track groove 5 of the inner ring 6 to transmit torque, and between the inner spherical surface 1 of the outer ring 3 and the outer spherical surface 4 of the inner ring 6, the balls 7 And a cage 8 for holding the The cage 8 is provided with a plurality of pockets 9 for accommodating the balls 7 along the circumferential direction.

  The track groove 2 of the outer ring 3 includes a back-side track groove 2a in which the track groove bottom is an arc portion and an opening-side track groove 2b in which the track groove bottom is a straight portion parallel to the outer ring axis. The back side track groove 2a has its center of curvature O1 shifted from the joint center O in the axial direction toward the opening side of the outer ring 3. The track groove 5 of the inner ring 6 includes a back side track groove 5a in which the track groove bottom is a straight portion parallel to the inner ring axis, and an opening side track groove 5b in which the track groove bottom is an arc portion. The center of curvature O2 of the opening side track groove 5b is provided at an equal distance k away from the joint center O in the axial direction on the back side opposite to the center of curvature O1 of the back side track groove 2a of the outer ring 3.

  Further, the cage outer spherical surface 8a shifts its radius of curvature O3 from the joint center O in the axial direction toward the opening side of the cage 8, and the cage inner spherical surface 8b has its curvature center O4 moved from the joint center O in the axial direction to the cage outer spherical surface 8a. Is provided on the far side opposite to the center of curvature O3 by an equal distance k1. In this type of conventional constant velocity universal joint, the track offset amount of the inner and outer rings is increased, and the offset amount of the cage is decreased. Further, the pitch angle between two adjacent balls 7 is 60 degrees as shown in FIG. That is, six balls 7 are arranged at a pitch of 60 degrees along the circumferential direction.

  By the way, in recent years, it has been demanded that the fixed type constant velocity universal joint can be reduced in size and the torque load capacity can be increased. As a method for reducing the size of the fixed type constant velocity universal joint having six balls and increasing the torque load capacity, it is conceivable to place the largest possible ball on the smallest possible PCD. However, when a large ball is used, the column (window column) between the pockets of the cage becomes thin, and the rigidity of the cage decreases. In particular, for a torsional torque load at a high angle, the cage is easily damaged, which causes a decrease in strength of the constant velocity universal joint.

  In particular, as shown in FIG. 27, when the track offset amount of the inner and outer rings is large and the offset amount of the cage is small, the depth of the track groove on the inner side of the outer ring becomes shallow, and the torque load capacity at high angles becomes small. That is, the ball tends to ride on the track edge with respect to a torque load at a high angle, and an excessive stress is generated at the edge portion. For this reason, damage due to chipping of the edge portion or a locking phenomenon with the cage due to plastic deformation occurs. These damages and lock phenomena deteriorate the operability, reduce the durability life, and cause the cage to break. In addition, the inner ring has a shallower track depth on the back side, and has the same drawbacks as the outer ring. For this reason, improvement of joint strength and durability in a high angle region is a conventional problem.

  Therefore, conventionally, by increasing the circumferential length dimension of the pillar portion existing between the pockets adjacent in the circumferential direction to ensure the durability of the cage, the durability of the entire constant velocity universal joint is improved. There is one designed to improve (Patent Document 1). That is, the one described in Patent Document 1 stores a plurality of balls in one pocket, thereby narrowing the interval between the balls stored in the same pocket, and between adjacent pockets in the circumferential direction. In this case, the circumferential length of the pillar portion existing in is increased, and the number of balls is seven or more.

Conventionally, there is one in which two are stored in each pocket of the cage to suppress periodic fluctuation of the moment during rotation (Patent Document 2). That is, the thing of this patent document 2 makes the circumferential direction length of one window pillar large by making all the pockets of a cage into the long window which made the circumferential direction space | interval large.
Japanese Patent Laid-Open No. 11-303882 British patent 1537067

  In the thing of patent document 1, the circumferential direction length dimension of the pillar part which exists between pockets adjacent in the circumferential direction is enlarged by accommodating a plurality of balls in a pocket, and the durability of the cage In order to ensure, the durability of the constant velocity universal joint as a whole is improved. However, the one described in Patent Document 1 is based on the premise that the number of balls is seven or more, and in the case of having six balls, the load capacity decreases at high angles and the contact between the inner ring and the cage inner spherical surface. It is not intended to prevent an increase in surface pressure.

  Moreover, in the thing of patent document 2, two pieces are accommodated in each pocket of a cage, and like the said patent document 1, the whole number of pockets is decreased and the circumferential direction length of a window pillar is enlarged. . For this reason, even in this case, it is not possible to prevent a decrease in load capacity at a high angle and an increase in contact surface pressure between the inner ring and the cage inner spherical surface.

  In view of the above problems, the present invention can be downsized, and even when downsized, when the operating angle is taken, there is little reduction in load capacity, and the ball rides on the track at high angles. A fixed type constant velocity universal joint capable of improving high angle strength and durability by relaxing the above is provided.

  The fixed type constant velocity universal joint according to the present invention includes an outer member having a plurality of track grooves formed on an inner spherical surface, an inner member having a plurality of track grooves formed on the outer spherical surface, and a track groove of the outer member. A plurality of balls that are interposed between the track grooves of the inner member and the track groove of the inner member, and a cage that has a pocket for accommodating the balls and is interposed between the outer member and the inner member. In the fixed constant velocity universal joint provided, the cage pocket has four pairs of a pair of long pockets having a large circumferential interval and a pair of short pockets having a small circumferential interval. Are shifted 180 degrees along the circumferential direction, and the pair of short pockets are shifted 180 degrees along the circumferential direction, and the long pockets and the short pockets are alternately arranged along the circumferential direction. Accommodates balls and short The socket accommodates one ball, is provided with a least chamfered portion in one of the edge portion of the cage outer spherical surface side and the cage spherical side of the long pockets.

  In the fixed type constant velocity universal joint of the present invention, the number of window columns between the pockets of the cage can be four, and the circumferential length of one window column can be increased. Thereby, the rigidity of each cage window column can be increased. By having a long pocket, it is easy to incorporate the inner ring into the cage.

  If the chamfered portion provided in the long pocket is formed on the edge of the cage outer spherical surface on the joint opening side, the inlay edge of the opening (inlet) of the outer member when this constant velocity universal joint takes an operating angle It is possible to have no pocket edge part on the outer spherical surface side of the cage that interferes with the part. In addition, if the chamfered portion provided in the long pocket is formed on the edge of the inner spherical surface of the cage on the inner side of the joint, when the constant velocity universal joint takes an operating angle, the inner edge of the outer spherical surface of the inner member It is possible to have no pocket edge portion on the spherical surface inside the cage that interferes with the portion.

  The chamfered portion may be formed over the entire circumference of the long pocket or may be formed only on the long side of the long pocket. That is, when the chamfered portion is formed over the entire circumference of the long pocket, when the chamfered portion is formed at the pocket edge portion on the cage outer spherical surface side, the chamfered portion is formed over the entire circumference of the cage outer spherical surface side. When forming the pocket edge portion on the inner spherical surface side, it is formed over the entire circumference on the inner spherical surface side of the cage. In addition, when forming only on the long side of the long pocket, when forming on the pocket edge on the cage outer spherical surface side, it should be formed on the long side of the cage outer spherical surface side and on the pocket edge portion on the cage inner spherical surface side. When forming, it is formed on the long side of the spherical surface inside the cage.

  Another fixed constant velocity universal joint of the present invention includes an outer member having a plurality of track grooves formed on an inner spherical surface, an inner member having a plurality of track grooves formed on the outer spherical surface, and the outer member. A cage interposed between the outer member and the inner member, having a plurality of balls that transmit torque by being interposed between the track groove and the track groove of the inner member, and a pocket that accommodates the balls In the fixed type constant velocity universal joint, the pocket of the cage has four pairs of a pair of long pockets having a large circumferential interval and a pair of short pockets having a small circumferential interval. The long pockets are shifted 180 degrees along the circumferential direction, and the pair of short pockets are shifted 180 degrees along the circumferential direction, and the long pockets and the short pockets are alternately arranged along the circumferential direction. Contains two balls and The short pockets accommodates one ball, the cage outer spherical surface, is provided with a notch as the inner surface and the non-contact of the outer member.

  In another fixed type constant velocity universal joint of the present invention, like the fixed type constant velocity universal joint of the first aspect, the rigidity of each cage window column can be increased, and further, by having a long pocket, the inner ring Can be easily assembled into a cage.

  In addition, since the outer spherical surface of the cage is provided with a cutout portion that is not in contact with the inner diameter surface of the outer member, when the constant velocity universal joint takes an operating angle, an inlay edge portion of the opening (inlet) of the outer member Interference with the pocket edge portion on the outer spherical surface side of the cage can be avoided.

The pitch angle on the PCD of the two balls accommodated in the long pockets was made smaller than 60 degrees, and the pitch angles of the other balls were made larger than 60 degrees. Specifically, the pitch angle (e) formed by two straight lines passing through the two centers on the pitch circle diameter (PCD) and the joint center of the two balls accommodated in the long pocket is made smaller than 60 degrees. And two straight lines passing through two centers on the pitch circle diameter (PCD) and the joint center of one ball accommodated in the long pocket and a ball accommodated in the short pocket adjacent to the long pocket. The pitch angle (d) formed by is made larger than 60 degrees. Thus, the pitch distance between the two balls yield capacity in the long pocket is reduced, the pitch distance between the track grooves of the outer member corresponding thereto becomes smaller.

  The axial length of the inner member was made shorter than the circumferential interval between the long pockets. This makes it easier to incorporate the inner member into the cage. Furthermore, the shoulder width dimension between the two track grooves of the outer member corresponding to the long pocket of the cage was set smaller than the pocket width in the cage axial direction. This facilitates the incorporation of the cage into the outer ring.

The center of curvature of the track groove of the outer member and the center of curvature of the track groove of the inner member are offset in the axial direction by an equal distance from the joint center, and the center of curvature of the outer spherical surface of the cage and the cage The center of curvature of the inner spherical surface was offset in the axial direction by an equal distance from the joint center, and the offset amount of the cage was increased so as to be substantially the same as the offset amount of the track groove. Specifically, the cage offset amount k2 and the track groove offset amount k are set to (k−k2) /k≦0.3. As a result, it is possible to prevent the depth of the track groove on the deeper side of the joint from becoming shallow, and to increase the thickness (diameter thickness) of the cage on the opening side.

  In addition, as a fixed type constant velocity universal joint, even if the track groove bottoms of the inner member and the outer member are provided with arc portions and straight portions, the track groove bottoms of the inner member and the outer member are arc shapes. A part and a taper part may be provided.

  In the present invention, since the rigidity of each cage window column can be increased, a large ball can be disposed on a small PCD, and the size can be reduced without reducing the load capacity. Moreover, the cage can be prevented from being damaged by a torsional torque load at a high angle. Further, by having the long pocket, the inner ring can be easily assembled into the cage. In particular, by making the axial length of the inner ring shorter than the minimum length of the long pockets in the circumferential direction, the inner ring can be more easily assembled into the cage and the assembly workability can be improved.

  If the chamfered portion is provided at the edge of the long pocket on the cage outer spherical surface side on the joint opening side, or the notch portion that is not in contact with the inner diameter surface of the outer member is provided on the cage outer spherical surface, Interference between the in-row edge of the opening (entrance) and the pocket edge on the outer spherical surface side of the cage can be avoided, and a chamfered portion is provided on the edge of the long pocket on the inner spherical surface side of the cage on the back of the joint. For example, interference between the inner edge of the outer spherical surface of the inner member and the pocket edge of the inner spherical surface of the cage can be avoided. For this reason, it becomes easy to guide to the inner spherical surface of the outer member of the cage and the outer spherical surface of the inner member, it is possible to prevent deterioration of the operability of the joint, and to prevent deterioration of the operability of the joint by improving the rigidity of the window frame. Together, it can effectively prevent the cage from cracking and cracking.

  The distance between the pitches of the two balls stored in the long pocket can be reduced, and the distance between the pitches of the track grooves of the outer member corresponding thereto can be reduced. This facilitates the incorporation of the cage into the outer ring. In particular, the distance between the pitches (the shoulder width dimension between the track grooves) can be made smaller than the pocket width in the cage axial direction, which makes it easier to incorporate the cage into the outer ring and improve the assembly workability. it can.

  The cage offset has been increased to be approximately the same as the track groove offset, so that the depth of the track groove on the inner side of the joint can be prevented from decreasing, and the cage wall thickness (radial thickness) on the opening side can be prevented. Can be increased. For this reason, it is possible to prevent the ball at a high angle from riding on the track edge, and an excessive stress does not act on the edge. In other words, the torsional torque load capacity at high angles is prevented from decreasing, and the high-angle durability life is improved (improved), and the breaking strength is improved (improved) due to plastic deformation of the inner and outer member track grooves at high angles. Can be planned.

  Further, since the thickness (diameter thickness) of the cage on the joint opening side can be increased, the rigidity of the cage window frame on the joint opening side can be increased. For this reason, coupled with the increased rigidity of each cage window column, it is possible to greatly improve the cage breakage strength against a torsional torque load at a high angle.

  If two balls are stored in the long pocket, there is no window column between the balls. Therefore, it is necessary to increase the rigidity of the window frame on the joint opening side that receives a large load from the balls. As described above, by increasing the offset amount of the cage so as to be substantially the same as the offset amount of the track groove, the rigidity of the window frame on the joint opening side can be increased, and two balls are stored in the long pocket. Even with the structure, the strength of the cage can be sufficiently maintained.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the fixed type constant velocity universal joint includes an outer ring 23 as an outer member in which a plurality of track grooves 22 are formed in the inner spherical surface 21 along the axial direction at unequal intervals in the circumferential direction. A plurality of track grooves 25 that are paired with the track grooves 22 of the outer ring 23 on the spherical surface 24 are formed along the axial direction at unequal circumferential intervals, and an inner ring 26 as an inner member, and the track grooves 22 of the outer ring 23 A plurality of balls 27 that transmit torque by being interposed between the track grooves 25 of the inner ring 26 and a cage 28 that is interposed between the inner spherical surface 21 of the outer ring 23 and the outer spherical surface 24 of the inner ring 26 to hold the balls 27. And.

  The track groove 22 of the outer ring 23 includes a back-side track groove 22a in which the track groove bottom is an arc portion and an opening-side track groove 22b in which the track groove bottom is a straight portion parallel to the outer ring axis. The back side track groove 22 a has its center of curvature O 1 shifted from the joint center O in the axial direction toward the opening side of the outer ring 23. The track groove 25 of the inner ring 26 includes a back side track groove 25a in which the track groove bottom is a straight portion parallel to the inner ring axis and an opening side track groove 25b in which the track groove bottom is an arc portion. The center of curvature O2 of the opening side track groove 25b is provided at an equal distance k away from the joint center O in the axial direction on the far side opposite to the center of curvature O1 of the back side track groove 22a of the outer ring 23.

  In the cage 28, the center of curvature O3 of the outer spherical surface 28a and the center of curvature O4 of the inner spherical surface 28b are offset in the axial direction by an equal distance k2 with respect to the joint center (cage center) O. The amount is made substantially the same as the offset amount of the track groove.

  For this reason, the outer spherical surface 28a of the cage 28 can form a substantially concentric arc (a concentric arc having different curvature radii) with the groove bottom of the inner track groove 22a of the outer ring 23, and the track groove depth on the inner side of the joint. Can be prevented, and the thickness (diameter thickness) on the opening side of the cage 28 can be increased.

  The cage 28 is provided with a pocket 29 for accommodating the ball 27. In this case, as shown in FIG. 2, the pockets 29 of the cage 28 have four pairs of a pair of long pockets 30 having a large circumferential interval and a pair of short pockets 31 having a small circumferential interval. . Then, the pair of long pockets 30 are shifted 180 degrees along the circumferential direction, and the pair of short pockets 31 are shifted 180 degrees along the circumferential direction so that the long pockets 30 and the short pockets 31 are alternately positioned along the circumferential direction. Is arranged. For this reason, there are four window columns (cage window columns) 33 provided between the pockets. The long pocket 30 accommodates two balls 27 and the short pocket 31 accommodates one ball 27.

  The pitch angle e on the PCD of the two balls 27 accommodated in the long pocket 30 is made smaller than 60 degrees, and the pitch angle d of the other balls 27 is made larger than 60 degrees. Further, the axial length i (see FIG. 7) of the inner ring 26 is made shorter than the circumferential interval h (see FIG. 6) of the long pockets 30. Further, as shown in FIG. 8, the shoulder width dimension f between the two track grooves of the outer ring 23 corresponding to the long pocket 30 of the cage 28 is set smaller than the pocket width g in the cage axial direction. An inlay portion 32 is formed on the joint opening side of the inner spherical surface of the cage 28.

  By the way, as shown in FIGS. 3 and 4, chamfered portions (chamber portions) 35 and 36 are formed in the long pocket 30 over the entire circumference of the edge portion on the outer spherical surface 28a and inner spherical surface 28b side. Yes. In this embodiment, as shown in FIG. 5, the chamfered portions 35 and 36 are tapered surfaces. However, as shown in FIG. 16, these chamfered portions 35 and 36 may be formed with rounded portions.

  According to the fixed type constant velocity universal joint of the present invention, the number of the window pillars 33 between the pockets of the cage 28 can be four, and the circumferential length of each window pillar 33 can be increased. . As a result, the rigidity of each cage window column 33 can be increased, so that a large ball 27 can be arranged on a small PCD, and the fixed constant velocity universal joint can be made compact without reducing the load capacity. As a result, the cage 28 can be reduced in size, and the cage 28 can be prevented from being damaged by a torsional torque load at a high angle.

  Incidentally, as shown in FIGS. 21 and 22, it is also possible not to provide the chamfered portions 35 and 36. However, when the chamfered portions 35 and 36 are not provided, the following problems occur.

  Further, when the constant velocity universal joint takes an operating angle, as shown in FIGS. 23 and 24, an inlay edge portion 37 of the opening (inlet) of the outer member, a pocket edge portion 38 on the cage outer spherical surface side, 25 and FIG. 26, the outer edge 40 of the inner spherical surface of the inner member interferes with the pocket edge 39 of the cage inner spherical surface. For this reason, the operability is deteriorated, chipping or cracking of the window edge occurs, leading to early breakage of the joint.

  On the other hand, in the present invention, by providing the chamfered portion 35 at the edge portion of the long pocket 30 on the cage outer spherical surface 28a side on the joint opening side, when an operating angle as shown in FIG. 9 is taken, As shown in FIG. 10, the pocket edge portion 38 on the cage outer spherical surface side that interferes with the inlay edge portion 37 of the opening (entrance) of the outer member can be omitted.

  Further, when the chamfered portion provided in the long pocket 30 is provided at the edge portion of the long pocket on the inner spherical surface side of the cage on the back side of the joint, when the operating angle as shown in FIG. The pocket edge portion 39 on the inner spherical surface side that interferes with the inner edge portion 40 of the spherical surface 24 may not be provided. For this reason, it becomes easy to guide to the inner spherical surface 21 of the outer member of the cage 28 and the outer spherical surface 24 of the inner member, so that the operability of the joint can be prevented from being deteriorated, and the operability of the joint is improved by improving the rigidity of the window frame. Combined with the prevention of deterioration, chipping and cracking of the cage 28 can be effectively prevented.

  Further, since the long pocket 30 is provided, the inner ring 26 can be easily assembled into the cage 28. In particular, by making the axial length i of the inner ring 26 shorter than the circumferential interval h of the long pockets 30, the inner ring 26 can be more easily assembled into the cage 28 and the assembly workability can be improved. .

  That is, when the inner ring 26 is incorporated in the cage 28, the inner ring 26 is disposed so that the axis is perpendicular to the axis of the cage 28 (the state in which the inner ring 26 is rotated by 90 ° with respect to the cage 28). Then, a part of the outer spherical surface 24 of the inner ring 26 is dropped into the pocket 29 of the cage 28. In this state, the inner ring 26 is inserted into the cage 28, and then the inner ring 26 is rotated by 90 ° with respect to the cage 28. The axis of the inner ring 26 is aligned with the axis of the inner ring 26 and is placed in a normal posture. For this reason, when the inner ring 26 is assembled into the cage 28, a part of the outer spherical surface 24 of the inner ring 26 can be dropped into the long pocket 30 and the inner ring 26 can be easily assembled into the cage.

  Further, the distance between the pitches of the two balls 27 accommodated in the long pocket 30 can be reduced, and the distance between the pitches of the track grooves 22 of the outer ring 23 corresponding thereto can be reduced. This facilitates the incorporation of the cage 28 into the outer ring 23. In particular, the pitch distance (track groove shoulder width dimension f) can be made smaller than the pocket width g in the cage axis direction, which makes it easier to incorporate the cage 28 into the outer ring 23 and enhances assembly workability. Can be improved.

  Since the offset amount of the cage 28 is increased so as to be substantially the same as the offset amount of the track grooves 22 and 25, it is possible to prevent the depth of the track groove on the back side of the joint from becoming shallow and to prevent the meat of the cage 28 on the opening side. The thickness (thickness in the radial direction) can be increased. For this reason, it is possible to prevent the ball at a high angle from riding on the track edge, and an excessive stress does not act on the edge. In other words, the torsional torque load capacity at high angles is prevented from decreasing, and the high-angle durability life is improved (improved), and the breaking strength is improved (improved) due to plastic deformation of the inner and outer member track grooves at high angles. Can be planned.

  If the two balls 27 are stored in the long pocket 30, the window pillar 33 does not exist between the balls 27. Therefore, it is necessary to increase the rigidity of the window frame on the joint opening side that receives a large load from the balls 27. However, as described above, by increasing the offset amount of the cage 28 so as to be substantially the same as the offset amount of the track grooves 22 and 25, the rigidity of the window frame on the joint opening side can be increased. Even in the structure in which the two balls 27 are accommodated in 30, the strength of the cage 28 can be sufficiently maintained.

  13 shows a case where the chamfered portion 36 is not provided on the cage inner spherical surface 28b side, and FIG. 14 shows a case where the chamfered portion 35 is not provided on the cage outer spherical surface 28a side. That is, in FIG. 13, interference between the inlay edge portion 37 of the opening (entrance) of the outer member and the pocket edge portion 38 on the cage outer spherical surface side can be avoided, and in FIG. 14, the outer spherical surface 24 of the inner member. Interference between the rear edge portion 40 of the inner wall and the pocket edge portion 39 on the spherical surface inside the cage can be avoided. Further, as shown in FIG. 15, the chamfered portion 35 may be provided only on the long side portions 41 and 41 of the long pocket 30.

  17 and 18 show another embodiment. In this case, the cage outer spherical surface 28a is provided with notches 50a and 50b that are not in contact with the inner diameter surface 23a of the outer ring 23. FIG. Each notch 50a, 50b is semi-elliptical when viewed from the outside, and the notch 50a of the long side 41a on one side (joint opening side) is the notch 50b of the long side 41b on the other (joint back side). It is formed larger than.

  Thus, in the constant velocity universal joint using the cage 28 in which the notches 50a and 50b are formed, when the operating angle as shown in FIG. 19 is taken, the opening (inlet) of the outer ring 23 as shown in FIG. The interference of the inlay edge portion 37 can be avoided.

  That is, even the cage 28 shown in FIGS. 17 and 18 can effectively prevent the cage 28 from being chipped or cracked.

  By the way, in the said embodiment, although it was an undercut free type | mold (UJ) which has the straight grooves 22b and 25a in the track grooves 22 and 25 as a fixed type constant velocity universal joint, it is a bar which does not have such a straight groove. Field type (BJ) may be used. Moreover, the track groove bottoms of the inner ring 26 and the outer ring 23 may be provided with an arc portion and a tapered portion. In this case, it is preferable to provide the taper portion of the track groove 22 of the outer ring 23 on the opening side and to expand from the back side toward the opening side. This is because the operating angle can be increased.

As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the embodiment, the curvature center O1 and the curvature center O3 are slightly different. Although the center of curvature O2 and the center of curvature O4 are disposed at positions slightly deviated from each other, the center of curvature O2 is provided even if the center of curvature O1 and the center of curvature O3 are the same position. And the center of curvature O4 may be at the same position. Further, when the curvature center O1 and the curvature center O3 are shifted, or when the curvature center O2 and the curvature center O4 are shifted, the shift amount can be arbitrarily set, but the offset amount k and the shift amount (k−k2). Is preferably set as (k−k2) /k≦0.3. (K-k2) / k> becomes 0.3, run out of conventional fixed type constant velocity universal joint and differences shown in FIG. 2 7, together with the track groove depth of the joint back side becomes shallow, the opening side cage 28 the thickness of the can no longer increase, below the required strength of the joint (see FIG. 2 9).

  Further, the circumferential interval h of the long pockets 30 can be set in various ways within a range in which the ease of assembling the cage 28 into the inner ring 26 can be improved and the rigidity of the window pillar 33 is not lowered. Furthermore, the track groove shoulder width dimension f, the pocket width g of the cage 28 in the cage axial direction, and the like can be set in consideration of the ease of incorporation of the cage 28 into the outer ring 23 and the like.

It is sectional drawing of the fixed type constant velocity universal joint which shows embodiment of this invention. It is principal part sectional drawing of the said fixed type constant velocity universal joint. It is sectional drawing of the cage of the said fixed type constant velocity universal joint. It is a side view of the cage of the fixed type constant velocity universal joint. It is principal part sectional drawing of the cage of the said fixed type constant velocity universal joint. It is a cross-sectional view of the fixed type constant velocity universal joint. It is sectional drawing of the inner ring | wheel of the said fixed type constant velocity universal joint. It is sectional drawing which shows the relationship between the outer ring | wheel of the said fixed type constant velocity universal joint, and a cage. It is sectional drawing which shows the relationship between the inlay edge part of the outer ring | wheel of the said fixed type constant velocity universal joint, and the chamfering part of a cage. FIG. 10 is an enlarged cross-sectional view of a main part of FIG. 9. It is sectional drawing which shows the relationship between the back side edge part of the inner ring | wheel of the said fixed type constant velocity universal joint, and the chamfering part of a cage. It is a principal part expanded sectional view of the said FIG. It is sectional drawing which shows the 1st modification of the cage of the said fixed type constant velocity universal joint. It is sectional drawing which shows the 2nd modification of the cage of the said fixed type constant velocity universal joint. It is a side view which shows the 3rd modification of the cage of the said fixed type constant velocity universal joint. It is sectional drawing of the modification of the chamfering part of a cage. It is a side view of the cage of the other fixed type constant velocity universal joint which shows embodiment of this invention. FIG. 18 is a side view of the cage of FIG. 17. It is principal part sectional drawing of the constant velocity universal joint which uses the cage of the said FIG. It is principal part sectional drawing of the said FIG. It is a side view which shows the comparative example of the cage of a constant velocity universal joint. FIG. 22 is a perspective view of the cage of FIG. 21. It is principal part sectional drawing of the constant velocity universal joint which uses the cage of the said FIG. It is a principal part expanded sectional view of the said FIG. It is principal part sectional drawing of the constant velocity universal joint which uses the cage of the said FIG. It is a principal part expanded sectional view of the said FIG. It is a longitudinal cross-sectional view of the conventional constant velocity universal joint. It is a cross-sectional view of a conventional constant velocity universal joint. It is a figure which shows the relationship between offset amount k and deviation | shift amount (k-k2).

Explanation of symbols

21 inner spherical surface 22 track groove 24 outer spherical surface 25 track groove 26 inner ring 27 ball 28 cage 28b inner spherical surface 28a outer spherical surface 29 pocket 30 long pocket 31 short pocket 35 chamfered portion 36 chamfered portion 41a long side portion 41b long side portion 50a notch Part 50b Notch

Claims (8)

An outer member having a plurality of track grooves formed on the inner spherical surface, an inner member having a plurality of track grooves formed on the outer spherical surface, and between the track grooves of the outer member and the track grooves of the inner member. In a fixed type constant velocity universal joint including a plurality of balls interposed and transmitting a torque, and a cage having a pocket for accommodating the balls and interposed between an outer member and an inner member,
The cage pocket has four pairs of a pair of long pockets having a large circumferential interval and a pair of short pockets having a small circumferential interval, and the pair of long pockets are shifted by 180 degrees along the circumferential direction. In addition, the pair of short pockets are shifted 180 degrees along the circumferential direction, the long pockets and the short pockets are alternately arranged along the circumferential direction, and the two pockets are accommodated in the long pockets. A fixed type constant velocity universal joint which accommodates one ball and is provided with a chamfered portion at least one of an outer spherical surface side and an inner spherical surface edge portion of the long pocket.   2. The fixed type constant velocity universal joint according to claim 1, wherein the chamfered portion is formed over the entire circumference of the long pocket.   2. The fixed type constant velocity universal joint according to claim 1, wherein the chamfered portion is formed only on the long side of the long pocket. An outer member having a plurality of track grooves formed on the inner spherical surface, an inner member having a plurality of track grooves formed on the outer spherical surface, and between the track grooves of the outer member and the track grooves of the inner member. In a fixed type constant velocity universal joint including a plurality of balls interposed and transmitting a torque, and a cage having a pocket for accommodating the balls and interposed between an outer member and an inner member,
The cage pocket has four pairs of a pair of long pockets having a large circumferential interval and a pair of short pockets having a small circumferential interval, and the pair of long pockets are shifted by 180 degrees along the circumferential direction. In addition, the pair of short pockets are shifted 180 degrees along the circumferential direction, the long pockets and the short pockets are alternately arranged along the circumferential direction, and the two pockets are accommodated in the long pockets. Is a fixed type constant velocity universal joint characterized in that a single ball is accommodated and a cutout portion is formed on the outer spherical surface of the cage so as not to contact the inner diameter surface of the outer member. The pitch angle (e) formed by two straight lines passing through the two centers on the pitch circle diameter ( PCD ) and the joint center of the two balls accommodated in the long pocket is made smaller than 60 degrees, Two straight lines passing through two centers on the pitch circle diameter (PCD) and the joint center of one ball accommodated in the long pocket and the ball accommodated in the short pocket adjacent to the long pocket. The fixed type constant velocity universal joint according to any one of claims 1 to 4, wherein a pitch angle (d) formed by is greater than 60 degrees.   The fixed type constant velocity universal joint according to any one of claims 1 to 5, wherein an axial length of the inner member is shorter than a circumferential interval between the long pockets.   The fixed type according to any one of claims 1 to 6, wherein a shoulder width dimension between two track grooves of the outer member corresponding to the long pocket of the cage is set smaller than a pocket width in the cage axial direction. Constant velocity universal joint. The center of curvature of the track groove of the outer member and the center of curvature of the track groove of the inner member are offset in the axial direction by an equal distance from the joint center, and the center of curvature of the outer spherical surface of the cage and the cage The center of curvature of the inner spherical surface is offset in the opposite axial direction by an equal distance from the joint center, and the offset amount k2 of the cage and the offset amount k of the track groove are (k−k2) /k≦0.3. either a fixed type constant velocity universal joint of claim 1 to claim 7, characterized in that the the.

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